PMU Hardware performance counter "not supported" in tegra-demo-distro image linux kernel ver 6.6

[saravanan.kadambathursubr]

In Jetson agx orin devkit with OE4T/tegra-demo/kernel ver 6.6 , “perf stat” command for hardware performance counter returns below error. Also “perf list” command not displaying “Hardware events”.

Log:

root@p3737-0000-p3701-0005:/perftool# ./perf stat -e cycles ls
perf
Performance counter stats for ‘ls’:
cycles
0.001991712 seconds time elapsed
0.000000000 seconds user
0.002304000 seconds sys

root@p3737-0000-p3701-0005:/perftool# ./perf list

List of pre-defined events (to be used in -e or -M):

alignment-faults [Software event]
bpf-output [Software event]
cgroup-switches [Software event]
context-switches OR cs [Software event]
cpu-clock [Software event]
cpu-migrations OR migrations [Software event]
dummy [Software event]
emulation-faults [Software event]
major-faults [Software event]
minor-faults [Software event]
page-faults OR faults [Software event]
task-clock [Software event]
tool:
duration_time
user_time
system_time
br_mis_pred OR armv8_cortex_a78/br_mis_pred/ [Kernel PMU event]
br_mis_pred_retired OR armv8_cortex_a78/br_mis_pred_retired/[Kernel PMU event]
br_pred OR armv8_cortex_a78/br_pred/ [Kernel PMU event]
br_retired OR armv8_cortex_a78/br_retired/ [Kernel PMU event]
bus_access OR armv8_cortex_a78/bus_access/ [Kernel PMU event]
bus_cycles OR armv8_cortex_a78/bus_cycles/ [Kernel PMU event]
…
…
scf_pmu/scf_cache_wb/ [Kernel PMU event]
rNNN [Raw hardware event descriptor]
cpu/t1=v1[,t2=v2,t3 …]/modifier [Raw hardware event descriptor]
[(see ‘man perf-list’ on how to encode it)]
mem:[/len][:access] [Hardware breakpoint]
alarmtimer:alarmtimer_cancel [Tracepoint event]
alarmtimer:alarmtimer_fired [Tracepoint event]
alarmtimer:alarmtimer_start [Tracepoint event]

root@p3737-0000-p3701-0005:/perftool# cat /etc/os-release
ID=tegrademo
NAME=“OE4Tegra Demonstration Distro”
VERSION=“5.0.11+snapshot-792d18b4cb2451b00280641403e6eaf37bd6e53f (master)”
VERSION_ID=5.0.11-snapshot-792d18b4cb2451b00280641403e6eaf37bd6e53f
VERSION_CODENAME=“master”
PRETTY_NAME=“OE4Tegra Demonstration Distro 5.0.11+snapshot-792d18b4cb2451b00280641403e6eaf37bd6e53f (master)”
CPE_NAME=“cpe:/o:openembedded:tegrademo:5.0.11+snapshot-792d18b4cb2451b00280641403e6eaf37bd6e53f”
root@p3737-0000-p3701-0005:/perftool#

---

root@p3737-0000-p3701-0005:/perftool# uname -a
Linux p3737-0000-p3701-0005 6.6.96-yocto-standard #1 SMP PREEMPT Tue Jul 8 18:26:33 IST 2025 aarch64 GNU/Linux

[DaneLLL]

Hi,
We don’t have much experience about running the commands. Do the commands work on AGX Orin developer kit with Jetpack 6.2.1?

[saravanan.kadambathursubr]

we are using OE4T/tegra-demo-distro kernel version 6.6 (L4T BSP layer - L4T R36.4.3/JetPack 6.2).

Yes the perf stat command works. By default the build doesn’t have the perf command, we added it in order to execute these test cases.

[DaneLLL]

Hi,
Please post your queries in
OE4T/tegra-demo-distro · Discussions · GitHub

So that the authors can check and provide suggestions. We generally work on standard Jetpack releases with sample Ubuntu rootfs. May not be able to suggest next for using this github rootfs.

[saravanan.kadambathursubr]

Ok. Thanks for your suggestion.